ADVERTISEMENT

The 2004 Scientific American 50 Award: Research Leaders

dancers performing a choreographed routine



MARKUS GREINER University of Colorado at Boulder

More In This Article

RESEARCH LEADER OF THE YEAR
Deborah S. Jin
Fellow, Joint Institute for Laboratory Astrophysics, Boulder, Colo.

Created a novel state of matter that might someday improve superconductors.

Superconducting wires convey electricity with perfect efficiency because the electrons inside overcome the natural mutual repulsion of their like charges, and pair up. The pairs then glide along without resistance. Yet how the pairs form and why they move so easily remain unclear, and materials scientists yearn for a way to study the phenomenon. Last year Deborah Jin and her colleagues provided what may be the perfect test bed by finding a way to pair up other members of the unsociable class of particles to which electrons belong: fermions.

Fermions, along with their opposites, bosons, comprise all the known matter in the universe. The two kinds of particles differ in a quantum-mechanical property called spin, which is an integer for bosons but an integer plus half for fermions. Because of this difference, at supercold temperatures only bosons can typically coalesce into the odd new form of matter that Albert Einstein and Satyendra Nath Bose predicted in 1924. Such a Bose-Einstein condensate was synthesized for the first time in 1995 by physicists at JILA, Jin's home institute. To make an equivalent Fermi condensate requires pairing off reluctant fermions so that their combined spin is an integer.

Other physicists had failed with complex laser setups, but Jin dared to take a simpler approach involving fewer lasers and just one kind of fermionic isotope (potassium 40) instead of two. In November 2003 she and her team produced a molecular condensate in which the paired fermions were chemically bound--an important landmark en route to the accomplishment but still short of the goal. A few weeks later Jin made the final leap to a true Fermi condensate, in which the paired but unbound fermions are comparable to the paired electrons in superconductors. Although fermions cannot be imaged directly, Jin devised a way to photograph a pattern that betrayed the fermionic state of the condensate.

Room temperature superconductors are not likely to materialize overnight from Jin's work, but many future improvements in superconductors will probably spring from it. The makers of the earlier Bose-Einstein condensate have already claimed a Nobel Prize for their accomplishment, and Jin seems a sure bet to eventually do the same.

AEROSPACE
Jet Propulsion Laboratory
Pasadena, Calif.

Demonstrated the power of robots to explore the planets.

The many probes the Jet Propulsion Laboratory had prowling the solar system this year greatly advanced our knowledge of the planets. In January twin Mars rovers Spirit and Opportunity touched down on opposite sides of the Red Planet, beaming images that provide the first indisputable proof that seas once existed on Mars and raising the odds of uncovering fossils or even life. At the same time, the Stardust spacecraft began its return to Earth after scooping up comet samples to shed light on the icy wanderers. In June the Cassini spacecraft arrived at Saturn successfully. So far Cassini has found two new moons there, and scientists hope that what the mission can tell them about Saturn's rings will also extend understanding of the disk of gas and dust that surrounded the early sun.

AGRICULTURE
Joseph Ecker
Professor of plant biology, Salk Institute for Biological Studies, La Jolla, Calif.

Made pioneering contributions in plant genomics.

Future improvements in agriculture depend on determining the functions of plant genes. In 2003 Joseph Ecker and his group made important contributions by identifying a number of key signaling components in the ethylene pathway of Arabidopsis, a plant commonly used as a model for genetic studies. The team showed that a transcription factor, responsible for turning on a gene, accounts for the response that prompts fruit to ripen in the presence of ethylene. In addition, Ecker, an early proponent and participant in sequencing the Arabidopsis genome, published an elegant experiment that identified most of the transcripts, or genetic coding, in the plant using a set of gene chips. By producing carefully indexed mutations in the genome, he and his co-workers have revolutionized plant biology, allowing researchers to ascertain easily the function of a particular gene by disabling or removing it. Because of his vision, it is now possible to obtain a mutant for most Arabidopsis genes by accessing public repositories.

AUTOMOTIVE
L. Craig Davis

Adjunct professor of physics, University of Michigan at Ann Arbor

Found that automated spacing of cars would help eliminate traffic jams.

As you always suspected, today's congested highways could better accommodate traffic if only people would drive with more precision and sense. That's the conclusion of Craig Davis, who used computer simulations to show that many traffic tie-ups could be avoided if just one in five vehicles on the road used adaptive cruise-control (ACC) technology, which employs radar to maintain a safe distance from another car or truck. Davis asserts in the June 2004 Physical Review E that extra spacing between vehicles is needed to account for sluggish human reaction times. When one motorist slams on the brakes, the vehicles following behind must often do the same. Overbraking by flesh-and-blood drivers can thus propagate backward, sometimes causing a jam. Smoother road maneuvers, such as those produced by ACC (which initiates braking almost instantaneously), would go a long way toward preventing such highway backups.

BIOMEDICAL ENGINEERING
Miguel A. L. Nicolelis

Professor of neurobiology medical engineering and psychological and brain sciences and co-director of the Center for Neuroengineering, Duke University

Enabled the brain waves of monkeys to control a robotic arm.

Macaque monkeys are leading the way toward a better future for people with paralyzed limbs. In the laboratory of Miguel Nicolelis, electrodes implanted in a monkey's brain enabled the primate to sit motionless yet still reach and grasp objects with a robotic arm. To accomplish this feat, Nicolelis and his colleagues first mapped the areas of the brain active when the monkey manipulated the robotic arm with a joystick; this information showed the correspondence between specific motions and brain signals. Then they disconnected the joystick from the robotic arm. The remaining link between the electrodes and the arm enabled the monkey to move the arm through thought alone. The work portends a day when disabled humans may be able to manipulate things merely with their thoughts.

CHEMICALS AND MATERIALS
Joseph Poon and Gary J. Shiflet
Poon, professor of physics, and Shiflet, professor of materials science, University of Virginia

Created amorphous steel that could strengthen skyscrapers and armor-piercing rounds.

The strength of conventional steel is limited by defects that inevitably pop up in the crystalline organization of its atoms. Joseph Poon and Gary Shiflet and their colleagues devised amorphous steel that lacks those defects because it has randomly arranged molecular bonds. The resulting metal has triple the strength of its crystalline counterpart and better corrosion resistance. Although scientists have created amorphous alloys in the past, Poon and his team reported in the May 2004 Journal of Materials Research a way to make amorphous steel in bulk. The secret was adding the element yttrium, which discourages crystallization as the molten steel solidifies. The metal can then be cast in molds or shaped in the same way plastic can. Separately, researchers at Oak Ridge National Laboratory also reported making amorphous steel in bulk. Intriguingly, both steels are nonmagnetic, which has raised the U.S. Navy's hopes of using the material in submarine and other hulls that could evade magnetic sensors.


COMMUNICATIONS
Neil Gershenfeld
Director, Center for Bits and Atoms, Massachusetts Institute of Technology

Designed communication protocol for connecting the hardware in a "smart" household.

Your alarm clock could someday alert your coffeepot to start brewing, while "smart" garden sprinklers could check the weather forecast online. Neil Gershenfeld brought these dreams a step closer to reality with his Internet Zero protocol, a standard for efficient communication between tiny networked devices placed around the home. The microcontrollers that implement this protocol can be manufactured for around $1, and each holds its own data, eliminating the need for a costly and potentially unreliable central server. Whereas similar systems developed by others emphasize speed, Gershenfeld's opts for versatility by translating signals directly into the Internet Protocol, a step that simplifies data transmission. In the future, Internet Zero may allow you to monitor and control your home from a PDA or cell phone.

COMPUTING
Mario Paniccia
Director of photonics technology laboratory, Intel Corporation, Santa Clara, Calif.

Built low-cost, mass-produced silicon circuits for high-speed optical switching.

Circuits that can quickly switch light have been limited to exotic semiconductors that are difficult and expensive to manufacture, making the components too costly for applications other than major fiber-optic networks. But in February an Intel team led by Mario Paniccia unveiled a modulator made from common silicon that can process one gigabit of data per second, 50 times faster than previous experimental devices. The modulator splits a light beam into two phases that either cancel or reinforce, creating the on-and-off pulses of electronic data. Paniccia has since used prototypes to send high-definition video data between two computers. Furthermore, he crafted the modulator on Intel's high-volume CMOS fabrication line, which cranks out the company's microprocessors. The combination of silicon and mass production promises products that will cost much less than current optical switches. Intel says the technology could lead to far faster connectors between servers in corporate data centers, between personal computers and servers, and eventually between chips inside PCs themselves.

DEFENSE
Thomas G. Thundat and Jesse Adams
Thundat, senior research scientist and leader of the nanoscale science and devices group at Oak Ridge National Laboratory; and Adams, assistant professor of mechanical engineering, University of Nevada at Reno

Developed miniature bomb detectors.

Bomb-sniffing dogs and mass-spectrometer chemical analyzers have become common sights at airports, but security specialists long for smaller, cheaper detectors that don't need to be plied with biscuits. Last year a team led by physicist Thomas Thundat and mechanical engineer Jesse Adams demonstrated a new scheme for TNT detection that seems at first like a rather bad idea: heat the suspected explosive to 1,000 degrees Celsius and see whether it blows up. Their sensor consists of a tiny cantilever about 200 microns long--like a diving board in a flea circus. TNT molecules wafting through the air stick to the cantilever, causing a stress that flexes it. An electric heater then detonates the TNT, releasing the stress so that the cantilever snaps back to its starting position. The piezoelectric material of the cantilever generates a distinctive voltage pattern as it bends. Although the explosion gives off a puff of smoke, the cantilever is unharmed. The prototype can pick up as little as 70 picograms of TNT, making it as sensitive as dogs and existing equipment. When a thin coating is added to the cantilevers, they can be adapted to detect plastic explosives or even disease proteins.

ECONOMIC DEVELOPMENT
Jack Keller
Founder and chief exeutive officer, Keller-Bliesner Enterprises, Logan, Utah, and member, board of directors, International Development Enterprises, Lakewood, Colo.

Designed small-scale irrigation and water conservation systems.

Crops will not grow without water, and small farms in developing countries cannot afford the costly, complex irrigation systems used by larger operations. International Development Enterprises, a nonprofit organization dedicated to helping small landowners increase agricultural productivity, began field-testing affordable new sprinkler and water storage systems designed by Jack Keller earlier this year. Keller's innovative water storage tanks hold 10,000 liters and cost just $40, and his drip irrigation and micro sprinkler systems provide hydration for as little as five cents per square meter. Using these water management tools, small farmers can increase production with fewer hours of labor. Such simple measures allow them to sell excess crops and help to alleviate poverty. Other systems designed by Keller have already been implemented in more than 50 countries.

ENERGY
Lanny D. Schmidt
Regents professor of chemical engineering, University of Minnesota

Developed the first chemical reactor that produces hydrogen from renewable fuel.

Hydrogen has been touted as the clean energy source of the future, but to achieve that rosy prospect, scientists must first overcome many challenges. Chief among those is the obstacle of wresting hydrogen from petrochemicals, water or other sources takes energy--energy that is very likely to come at the environmental price of carbon dioxide emissions or nuclear waste by-products. Transport and storage of hydrogen are also problematic. A team of University of Minnesota researchers led by Lanny Schmidt proposed this past February in Science a way to address many of these issues by producing hydrogen from ethanol via a chemical catalysis that requires little added energy. Renewable ethanol, though still energy-intensive to make, is relatively easy to distill from the cellulose in plant material such as corn, and it can be transported and stored easily. The researchers see an early use for their invention in remote areas far from an electrical grid, where the installation of new power lines is not feasible.

ENVIRONMENT
Gavin A. Schmidt and Drew T. Shindell
NASA Goddard Institute for Space Studies

Looked back millions of years for clues to global warming.

As researchers explore the impact of human activities on global climate, they are turning to the earth's past for valuable lessons. One of the most extreme episodes of global warming occurred about 55 million years ago during the transition between the Paleocene and Eocene epochs. For a period lasting less than 100,000 years, average temperatures at the high latitudes rose by up to seven degrees Celsius. In a paper published in Paleoceanography last year, Schmidt and Shindell showed that a tremendous eruption of methane from underneath the seafloor may well have caused the intense warming. This finding has important implications for future climate change because the amount of methane in the atmosphere has doubled in the past 200 years as a result of increased rice cultivation, livestock raising, coal mining and natural gas production.

IMAGING
Daniel Rugar
Manager of nanoscale studies, IBM Almaden Research Center, San Jose, Calif.

Made MRI details sharper than ever.

The power of magnetic resonance imaging (MRI) to peer into the body rests on its ability to detect the spins of subatomic particles. Even the best conventional MRI-based microscopes are sensitive only to groups of at least one trillion nuclear spins, however, limiting resolution to one micron. In the July 15 Nature, Daniel Rugar and his colleagues reported detecting the spin of a single electron, with rudimentary imaging at a resolution of just 25 nanometers. Their technique combines MRI with a microscopic cantilever sensitive enough to detect the infinitesimal forces a single electron spin exerts. In the future, Rugar hopes to pick up a single nuclear spin, whose signal is roughly 600 times weaker than an electron's, opening the door to microscopes yielding three-dimensional images of molecules with atomic detail.

MANUFACTURING
Micha Asscher
Chemist, Hebrew University of Jerusalem

Demonstrated how to grow nanostructures of nearly anything on anything else.

Assembling wires and other intricate structures on any surface can prove tricky because not all materials combine well. If a substance is built onto another with which it interacts weakly, the top layer can ball up. Conversely, pairs of materials that interact strongly can bond too tightly to weave into sophisticated patterns. In May, Micha Asscher and his colleagues revealed a way to lay down a pattern of almost any substance on any other for novel nanometer scale devices such as those used in microelectronics and catalysts. Their method deposits a layer of inert xenon--supercooled to a solid at roughly -250 degrees Celsius--between two substances. When this sandwich is heated, the xenon evaporates and the bottom layer absorbs the top one. The researchers say their method could make conducting wires less than 30 nanometers wide yet millimeters long.

MEDICAL DIAGNOSTICS
Francis Barany
Microbiologist, Weill Medical College of Cornell University

Invented chips for rapid detection of cancer and infections.

The mutations that lead to cancer can alter a variety of genes and be nearly indistinguishable from the normal DNA sequences around them. Francis Barany is creating devices that rapidly identify mutations to discover which ones cause tumors, a strategy that should enable more effective individualized cancer therapies. Barany is a leader in inventing critical technologies sensitive enough to work at the level of single proteins or nucleotides, the building blocks of DNA. Products based on Barany's patents have been developed by Applied Biosystems, Celera Diagnostics and New England Biolabs. In the past year, he helped to start a biodefense consortium that includes the Centers for Disease Control and Prevention, the FBI and Argonne National Laboratory, a collaboration intended to develop quick, cheap and precise gene-based biosensors to detect biowarfare pathogens.

MEDICAL PHYSIOLOGY
Peter G. Schultz
Organic chemist, Scripps Research Institute, La Jolla, Calif.

Expanded the genetic code's library of amino acids.

Nearly all life on earth is genetically coded to employ just 20 amino acids to make proteins, but rare exceptions also use one of two extra amino acids, selenocysteine and pyrrolysine. This fact of life raises the question of whether scientists can rewrite genetic codes to create proteins that could incorporate any of hundreds of synthetic amino acids invented over the years and that might have novel or superior properties. In the August 15, 2003, Science, Peter Schultz and his colleagues described how they engineered yeast that generated five such amino acids and wove them into proteins. Earlier, Schultz and others had genetically modified bacteria to produce unnatural amino acids. But yeast is a eukaryote, with a membrane-bound nucleus similar to the cells of humans. The team's accomplishment opens the door to applying the same techniques to higher organisms, potentially leading to new protein medicines.

MEDICAL TREATMENT
Nina Bhardwaj
Professor of medicine and director of the cancer vaccine program, New York University School of Medicine

Made progress toward creating dendritic cell vaccines.

Dendritic cells' key role in priming the immune system gives them formidable potential as therapeutic vaccines for fighting cancers and viruses such as HIV. These spiny cells' main job in the body is to display antigens--distinctive bits of undesirable invaders--to the immune system's foot soldiers, called killer T cells, for future recognition and attack. Nina Bhardwaj, already one of the world's leading experts on dendritic cells, significantly advanced prospects for dendritic cell vaccines this year with a series of discoveries about the cells' properties and behavior. Among these findings, Bhardwaj clarified several of the mechanisms that dendritic cells use to identify invaders and stimulate T cells. She also showed how tumor cells can suppress dendritic cells and, in another study, demonstrated that dendritic cells' activity appears not to be diminished by hepatitis C, a common co-infection in HIV patients. She is currently conducting two clinical trials of dendritic cell vaccines in HIV patients and planning for another vaccine trial in melanoma patients soon.

NANOTECHNOLOGY
Ehud Shapiro
Professor of computer science and applied mathematics, Wizmann Institute of Science, Israel

Made a DNA computer that diagnoses cancer and then releases a drug to treat it.

Ehud Shapiro's research group is known for having developed the world's smallest biological computing device, a DNA computer produced in 2002. Now it has put together a similar computer that releases a cancer-fighting drug if the correct conditions are met. The first part of the computer consists of short DNA strands that bind to four varieties of messenger RNA produced by genes involved in a specific cancer. The second component analyzes whether all four genes are abnormally active. If so, it triggers a third component to release a therapeutic piece of DNA that binds to a cancer gene to suppress it. The research group demonstrated the computer in test tubes, with messenger RNA levels adjusted by hand. Although such DNA computers could be decades from application in patients, it is a stunning proof of principle for a technology that might one day be used fo biochemical sensing and genetic engineering as well as for medical diagnosis and treatment.

PUBLIC HEALTH
Richard J. Webby
Assistant faculty member of the department of infectious diseases, St. Jude Children's Research Hospital, Memphis, Tenn.

Created method for making flu vaccines quickly.

Every year medical authorities recommend that people get a flu shot--notwithstanding the facts that the vaccine is sometimes in short supply or turns out to be for the wrong strain. Those problems stem in part from the need for vaccine makers to predict nearly a year in advance which flu strains may be abundant and how many vaccine doses to prepare. Richard Webby has adapted a technique known as plasmid-based reverse genetics to produce a vaccine much more rapidly. The technique was developed by Yoshihiro Kawaoka of the University of Wisconsin-Madison and further refined by Robert Webster and Erich Hoffman of St. Jude hospital. Webby translated this experimental knowledge into an actual avian flu strain for a vaccine in early 2003. That groundwork enabled him to quickly create another avian flu strain for the 2004 season, in collaboration with the U.S. Centers for Disease Control and Prevention and the British National Institute for Biological Standards and Control. The method cuts two to three months off the normal time needed to derive a vaccine strain, which allows vaccine makers to wait longer to see which flu strain is likely to dominate the next season and perhaps even to produce a vaccine during a pandemic.

ROBOTICS
Jos¿ del R. Mill¿n
Researcher, Dalle Molle Institute for Perceptual Artificial Intelligence, Martigny, Switzerland

Achieved progress toward a mind-controlled wheelchair.

Doctors call it being "locked in." Utterly paralyzed, tens of thousands of people are islands of pure thought, able to perceive the world, to feel, to dream, yet not able to communicate. For years, engineers and cognitive scientists have worked to unlock them by building brain-computer interfaces. Last year a team led by Spanish computer scientist Jos¿ del R. Mill¿n unveiled software that finally makes practical the taking of electroencephalogram readings through scalp electrodes. It can divine which of three mental states a person is in. Each user chooses states that produce distinguishable brain-wave patterns--say, doing arithmetic or imagining moving the left hand--and trains the system in a few hour-long sessions. These states are then used as "forward," "left" and "right" commands. As a test, volunteers maneuvered a small robot around a model house. They set the course, while the bot itself handled time-sensitive maneuvers such as avoiding obstacles. A mind-controlled wheelchair is still years away, but it is no longer an idea disconnected from reality.

Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Back To School

Back to School Sale!

12 Digital Issues + 4 Years of Archive Access just $19.99

Order Now >

X

Email this Article

X